If you find yourself downtown wondering what those three big glass orbs surrounded by the more rectangular steel and glass setting of corporate downtown Seattle might be, you have probably stumbled upon the Seattle Spheres.

As you probably know, Seattle is Amazon town. The latest addition to the Amazon campus are the Seattle Spheres, three glass orbs housing more than 40,000 tropical plants next to Amazon’s new Seattle HQ building ‘Day One’. They’re designed as a place where Amazon employees can go and meet or think and work creatively surrounded by 55-foot-high treetops and tropical plants sprouting from a 4,000-square-foot living wall amidst waterfalls and fish tanks with colorful fish, and maybe grab a quick snack or coffee from Renée Erickson’s General Porpoise. It is truly a beautiful and special spot inside, complete with suspended tree bridges and a “birds nest”, where you can sit and get your next bright idea.

The spheres were originally only open to the public through guided tours (which you can still book). Amazon has since decided to give the public unguided access two Saturdays each month, but admission is limited, and you must make a reservation in advance through the Spheres’ website.

They’re also fun to watch from the outside, though, if you’re in the neighborhood and weren’t lucky enough to secure one of the coveted tickets. The adjacent small public visitor center, The Understory, offers a self-guided tour about the Spheres and Amazon, but DOESN’T give access to the garden inside the Spheres.